Monday, April 14, 2008

Safety cement

Conventional concrete suffers from a number of problems such as low tensile strength and a tendency to shrink as it sets. It is also brittle, which makes it liable to fail suddenly.

Now Bjorn Birgisson and Charles Beatty at the University of Florida have developed a kind of glue that when added to the concrete mix binds the components tightly.

The glue, a form of polyvinyl acetate, ensures that any cracks propagate slowly, making the concrete far more ductile – like a metal – so that it fails more slowly. That should give more time to take action when a concrete structure starts to crack. The additive also reduces the amount of shrinkage that concrete undergoes when it dries.